M7.7 Flashcards
What must you ensure when working on de-energised circuits?
- external power is off
- battery is disconnected
- red safety tag is fitted
When working in fuel tanks or vapour areas, what is the maximum amount of power allowed in your tools?
0.02 millijoules of energy or heat
How far should wire bundles be kept from pipes carrying flammable liquids?
50mm
How far should wire bundles be kept from pipes carrying nonflammable liquids?
15mm
What is the minimum bend radius for single wires?
3 times the outer diameter (10 times is preferred)
What is the minimum bend radius for wire bundles?
6 times the outside diameter
Why are drip loops used?
To prevent liquid getting into a plug
How often should primary support clamps be placed?
Not exceeding 24 inches
At what temperature should plastic clamps not be used?
121 degrees
What is the preferred orientation of a clamp?
With the mounting screw above the wire bundle
What is a harpoon tie?
It is a zip tie but in a straight line that holds cable raceways
What type of fabric is used to tie up wire bundles?
Cotton, nylon, fibreglass (cotton needs to be waxed)
Where should you not use ties on wires?
Fuel tanks
What can you use to prevent chaffing of multiple wire bundles?
Sleeving or tape
What is the maximum number of splices allowed in a wire?
3
The what must every undesignated wire have?
Dead ended with caps or sleeves (4-6 inches of connectors)
Where is the super champ forbidden?
Crimping
What letter is used to denote short housing?
S
How is every 10th contact shown?
It is circled
If the contact is using letters what order do they go in?
- upper case
- lower case
- double upper case
What must every unused contact hole have?
Nylon or Teflon seal plugs
What are polarisation keys used for?
To prevent the wrong computer being inserted into a shelf
What does the shaded part of the polarisation key indicate?
The solid portion of the key
What are the two ways of removing a connector pin?
Rear and front release (inserted from rear)
What is the difference between crimping tools MS3191-1 and MS3191-4?
- MS3191-1 has three separate turrets
- MS3191-4 has one multi head turret
What are the two types of solder?
- tin lead alloy (soft solder)
- silver solder (hard solder)
What temperature does most tin lead alloy solder enter plastic state?
358.F
What is the peruse of flux?
To remove the oxide from surfaces to be soldered and good flow of solder
What are the four types of cores on a solder?
- single
- tri
- multi
- perforated
What is solder sleeve pigtails most commonly used for?
Attaching a shield ground wire to shielded cables
How many un-stripped wires are allowed per end cap?
Only one
What is the maximum number terminals on one stud?
Four
How many times can you bend a terminal?
Only once
What is the configuration of an A-type terminal block?
One block, 8 sockets, four busses, two contacts per bus
What is the configuration of an D-type terminal block?
One block, 8 sockets, two busses, four contacts per bus
What is the configuration of an C-type terminal block?
One block, 8 sockets,
One bus, eight common contacts
How do you ensure a low resistance connection for bonding leads?
Non-conduction paint and anodising films must be removed
What should be done after installation of aground?
Checked by measuring the resistance between ground and aircraft
How may volts are tests done at?
250v or 500v
What type of circuits must continuity testing be done on?
Ones with no power applied
What is ageing of a wire?
The health of the wire’s insulation relative to the conditions its been in
What tells you how to do maintenance and repairs on standard electrical items?
Electrical standard practices manual (ESPM)
What is flammable leakage zone?
An area where leakage of flammable liquid and vapours can occur
What grade of temperature should a repair of a wire harness e?
Temperature grade D
What are SWAMP areas?
Severe weather and moisture prone
What can chafing wires cause?
A short circuit
When would corrosion occur on wires, cables, grounds,connectors?
When there is a leak of water, acid, beach
